Don-Nan Improved Hollow Tube Pump

Prevent gas from traveling up the casing annulus

The improved hollow tube pump is efficient at moving gas through the pump and is designed for pumping underneath a packer, which prevents gas from traveling up the casing annulus. Using two lungers—with one acting as a hollow valve rod—and two barrels enables an extremely tight plunger-to-barrel fit, resulting in precise gas transference.

The extremely tight fit in this pump makes it suitable for use with little to no solids.

Maximize compression and extend valve life

The double-valve configuration helps to provide maximum compression and extend valve lifespan. The open cage at the top of the pump mimics the two-stage hollow valve rod pump by holding the hydrostatic pressure and enabling the lower traveling valve to easily open.

The improved hollow tube pump’s extremely rigid design effectively extends the life of the pump, rods, tubing, and gearbox by virtually eliminating destruction caused by gas pound and lock. Taking the idea of a hollow valve rod a step further, we gave this design a mercury plunger with greater wall thickness and a spray-metal coating for increased wear resistance and smooth operation.

An API-modified oversized cage increases the flow area inside the cage without a loss of strength, improves solids flow-though, and increases pump efficiency.